1. Field of the Invention
The present invention relates to a photographing module, and more particularly, to a photographing module with optical zoom for use within a digital camera or a cell phone camera.
2. Description of the Related Art
In recent years, with the increasing developments of consumer electronic products, the demand for digital consumer products is becoming even larger than before while product quality is becoming even more essential for consumers. Digital camera users, for example, hold higher standards towards shooting quality, hoping to capture their life moments with high-quality images.
However, most of the conventional digital cameras or cell phone cameras are either equipped with digital zoom only or with limited optical zoom. Instead of moving a camera zoom lens along an optical axis, digital zoom is achieved by magnifying an image, or by cropping and then magnifying an area of an image that has been shot with maximum pixels. Therefore, when comparing the cropped and magnified area of an image with the original image, the former contains fewer pixels. By contrast, in an optical zoom system, the focal length and the refraction angle of light are adjustable because the lens elements can move along the optical axis. Thus, with optical zoom, the magnified image will have the same amount of pixels as the original image; that is, comparing with using optical zoom, using digital zoom makes image quality poorer. For example, if an original image taken by a photographing system with digital zoom has 8 million pixels, after an area of the original image is cropped and magnified using digital zoom, the magnified image may have only 2 million pixels. By contrast, if an original image taken by a photographing system with optical zoom has 8 million pixels, the magnified image will have 8 million pixels as well; the zoom in/out operation does not affect the image quality.
Given the fact that a photographing module with digital zoom results in poor image quality, there remains a need in the art for an improved photographing module with optical zoom to resolve the aforementioned drawback.